Getting a new Bike?

I'm getting a new bike. I have a few questions I'd like to ask. First of all, what company makes the best bikes? I know that this is probably a lame/unanswerable question to ask (some companies make better bikes for certain purposes, some companies are better for certain things, bla bla bla), but I really want to hear the opinions of different people and I know there are probably some manufacturers I should stay away from.

Also, I do mountain biking but I ride on roads and bike trails just as frequently. When I do mountain biking, I go on some pretty rough terrain so I don't know if it'd be a good idea to get a hybrid. But I don't know how good of an idea it would be to be riding a mountain bike with full suspension when i'm trying to go fast enough on the road. Any ideas? I currently have a mountain bike that I got from toys r us when i was in high school (or maybe even middle school. I can't remember). It has full suspension but its pretty old.

Now I'm going to be going to George Mason university so I will be riding on the bike trail near DC a lot I suspect.

First pick your bike shop. They will (or should) check the assembly, tune the wheel spoke tension and generally make sure it is roadworthy and that it fits you correctly. This is far more important than the brand.
In the mid-range($5-800), they are all taiwanese frames with Shimano components. All good stuff but you have to pay big money to get anything noticabley better.
For mixed trail/road use, get a hardtail (front suspension) bike where the frame has threaded eyelets for a luggage rack and fenders. Something too flashy will be a thief magnet.
For university commuting a decent quality but trashy looking beater bike is a safer bet.